What is the $\Theta$-notation for the expression below? Select the correct answer. $\left(\frac{1}{3} ight)^{n}+2^{100)+81^{\log _{3} n}+n^{3} \lg \left(n^{7} ight) $ $\Theta\left(81^{\log _{3} n} ight)$ $\Theta\left(n^{3} \lg \left(n^{7} ight) ight)$ $\Theta\left(2^{100} ight) $ $\Theta\left(\left(\frac{1}{3} ight)^{n} ight) $ CS.VS. 1171